Many types of personal restraint systems are used in automobiles and other vehicles. Such systems include, for example, seat belts for use by adults and children of sufficient size, and child seats with associated restraints for use by toddlers and small children. The seat belts and restraints in these systems generally include buckles that couple two or more lengths of webbing together to restrain an occupant in their seat. In some instances, the buckle includes a switch to monitor the status of the buckle (e.g., latched or unlatched). Such switches typically include moving parts that generate a signal by, e.g., closing or opening an electrical circuit. A variety of issues can impair the operation of the moving parts. For example, contamination (e.g., dirt, grime, water, etc.) can hinder or prevent proper movement of the moving parts, or can otherwise prevent proper functioning of the switch.